1. Field of the Invention
The present invention generally relates to a flexible covering for reducing vapor, moisture, and/or bacterial transmission therethrough, and more particularly, to a flexible covering for at least a sleeping surface of a mattress, the covering having a flexibility sufficient to reduce localized concentration of pressure on a body positioned on the mattress as well as forming a vapor barrier for minimizing moisture, vapor and bacterial build-up within the core of the mattress
2. Discussion of the Background
Therapeutic mattresses, for example, as disclosed by U.S. Pat. No. 4,706,313, assigned to the assignee of the present application, are preferably adapted to the special requirements needed for extended use by bed-ridden patients. Additionally, the fabrics or coverings employed as bedding for therapeutic mattresses, such as disclosed by U.S. Pat. No. 4,525,409, are also specially chosen and adapted for use by people confined to bed over an extended period of time.
Such special requirements include the prevention of pressure sores as well as the build-up of moisture, vapor and bacteria within the core of the mattress. Typically, the moisture, vapor and bacteria are transmitted through a covering of the mattress to the core as a result of incontinence, perspiration as well as unintentionally spilled liquids.
A major cause of pressure sores is localized concentration of pressure on the body of the patient due to the weight of the patient pressing down onto the surface of the mattress. This concentration of pressure results in a compression of soft tissues and a corresponding reduction in blood flow which promotes the formation of decubitus ulcers and the like.
Conventional solutions for reducing the localized concentration of pressure include the use of pliant materials having sufficient flexibility to mitigate sheering, i.e., friction against the skin, when a patient moves or sinks into the mattress which might otherwise arise due to the use of less pliant materials.
Moisture and vapor build up in the core of the mattress is a problem because it provides a breeding ground for bacteria, causes unpleasant odors and presents a risk of cross-contamination with multiple patient use. Conventional solutions for reducing moisture, vapor and bacteria build-up include providing a mattress cover or envelope, formed of vinyl, rubber or other waterproof materials, at a sleeping surface of the mattress. However, the most effective waterproofing materials are thick, stiff and hard, resulting in a flexibility which is ineffective in preventing body sores resulting from pressure. On the other hand, more pliant waterproof fabrics, which have a flexibility sufficient to mitigate the formation of body sores, have been found to be ineffective in reducing moisture, vapor and bacteria build-up in the core.
A further deficiency of disclosed, therapeutic mattresses is the failure to recognize that moisture and bacteria buildup in the core of the mattress results not only from the transfer of liquids, but also from the transfer of moisture vapor.